Efficacy of subantimicrobial dosing with doxycycline. Point/counterpoint.

BACKGROUND: This article addresses the role of subantimicrobial dosing with doxycycline, or SDD, in the treatment of chronic periodontitis. The authors discuss and debate 10 issues with regard to SDD's utility as an adjunct to scaling and root planing.

TYPES OF STUDIES REVIEWED: The authors reviewed reports of controlled clinical trials that assessed the efficacy of SDD. The main focus of this article is data from the U.S. Food and Drug Administration's phase 3 clinical trial that evaluated the efficacy of SDD in terms of alterations of probing depth, clinical attachment levels and disease progression.

RESULTS: The authors compared data from test groups, which underwent root planing plus SDD, with data from control groups, which underwent root planing alone. The mean data suggest that SDD provides a defined but limited improvement of periodontal status when used in conjunction with scaling and root planing. Furthermore, several in vivo studies indicated that a nine-month course of SDD did not cause development of drug-resistant bacterial strains or alteration of the subgingival microbiota.

CLINICAL IMPLICATIONS: Some patients may benefit from SDD. However, there are several issues that should be clarified before widespread use of SDD is recommended for patients with chronic periodontitis. The evidence indicates that suppression of the bacterial challenge, which reduces the host response, is the most efficient way to control periodontal diseases.